Electronic device and battery pack

ABSTRACT

An electronic device includes a storing unit which is provided on a battery pack and which retains power information of the battery pack, an acquiring unit which is provided in the main unit and which acquires the power information of the battery pack from the storing unit, and a control unit which is provided in the main unit and which controls the operation of the main unit based on the power information of the battery pack.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/999,509, filed Nov. 30, 2004, and is based upon and claims thebenefit of priority from prior Japanese Patent Application No.2003-401774, filed Dec. 1, 2003, the entire contents of each of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic device and a battery packprovided therein. More specifically, the present invention relates to atechnology that optimizes operation control by acquiring powerinformation of a battery pack.

2. Description of the Related Art

Electronic devices include a type of device in which a main unitincluding various circuits, such as a driving circuit and a controlcircuit, is equipped with a battery pack and the main unit is driven byelectric power supplied from the battery pack. The type of device is,for example, an information processing device such as a personalcomputer.

This type of electronic device of the related art includes a device(e.g., Japanese Unexamined Patent Application Publication No.2003-259191) which detects the type and voltage of an installed batterypack and an ambient temperature around the battery pack, and whichcontrols the device operation in response to the detected battery packtype and voltage, and ambient temperature.

Due to the sophistication, etc., of electronic devices in recent years,the maximum power consumption tends to increase in some types ofelectronic devices. In some cases, there is a possibility that powerconsumption may exceed the power that can be supplied of a battery pack.Such an excess power consumption over the power that can be supplied ofthe battery pack may cause the power to unintentionally and suddenlyturn off. The power-off may cause a problem of data loss in, forexample, an information processing device such as a personal computer.

Accordingly, in order to prevent the above problem from occurring, inthe information processing device of the related art, such as a personalcomputer, a control circuit provided in a main unit, such as a powersaving circuit, measures power supplied from a battery pack to the mainunit at the time the power consumption exceeds a power threshold setbeforehand, and controls the power of a central processing unit (CPU).

In the case of preventing the unintentional sudden power-off by usingthe power saving circuit or the like, a problem occurs in that theproduction cost is increased by the need for the power saving circuit orthe like.

When power information of the main unit or the battery pack is changed,a parameter of the power saving circuit must be examined and reset eachtime.

In addition, it is possible to increase the number of cells in thebattery pack in order to cope with a rise in power consumption of theelectronic device. However, an increased number of cells enlarges thebattery pack, thus increasing the battery pack weight. This also causesa problem of requiring major design changes of the battery installationpart in which the battery pack is installed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an electronic deviceand a battery pack which overcome the above problems and which optimizeoperation control.

According to an aspect of the present invention, an electronic devicedriven by power supplied from a battery pack installed in a main unit ofthe electronic device is provided. The electronic device includes astoring unit, provided in the battery pack, for storing powerinformation of the battery pack, an acquiring unit, provided in the mainunit, for acquiring the power information of the battery pack, and acontrol unit, provided in the main unit, for controlling the operationof the main unit based on the power information of the battery packacquired by the acquiring unit.

According to the present invention, the power can be prevented fromunintentionally and suddenly turning off due to insufficiency of thepower that can be supplied.

In addition, it is not necessary to provide a main unit of an electronicdevice with a control circuit such as a power saving circuit. This canreduces the cost required for producing the electronic device.

Preferably, the power information of the battery pack is regularlystored by the storing unit, and the regularly stored power informationis continuously or intermittently acquired by the acquiring unit.

According to the present invention, operation control can be optimizedin response to a state of use on each occasion.

According to another aspect of the present invention, an electronicdevice driven by power supplied from a battery pack installed in a mainunit of the electronic device is provided. The battery pack has thereona detectable part for enabling detection of the type of the batterypack. The main unit has thereon a detecting part for reading thedetectable part to detect the type of the battery pack, and the mainunit includes a control unit for controlling the operation of the mainunit based on power information stored in the battery pack, whose typeis detected.

According to the present invention, a different type of battery pack canbe prevented from being mistakenly inserted.

Preferably, a housing for the battery pack has, on an outer surfacethereof, one of a detectable projection and a detectable recess as thedetectable part, and the main unit has, thereon, as the detecting part,one of a detecting recess into which the detectable projection is to beinserted and a detecting projection to be inserted into the detectablerecess.

According to another aspect of the present invention, a battery pack foruse in an electronic device including a detecting part for detecting thetype of the battery pack and control unit for performing operationcontrol based on power information stored in the battery pack, whosetype is detected, is provided. The battery pack supplies driving powerto a main unit of the electronic device when being installed in the mainunit of the electronic device. The battery pack is provided with adetectable part by which the type of the battery pack is detected suchthat the detectable part is read by the detecting part when the batterypack is installed in the main unit of the electronic device.

Preferably, a housing for the battery pack has, on an outer surfacethereof, one of a detectable projection or a detectable recess as thedetectable part, and the type of the battery pack is detected such thata detecting projection provided as the detecting part of the main unitof the electronic device is inserted into the detectable recess, or thedetectable projection is inserted into a detecting recess provided asthe detecting part of the main unit of the electronic device.

According to the present invention, it is ensured that the abovesimplified structure can prevent a battery pack from being mistakenlyinserted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electronic device in a state in whicha battery pack is separated from a main unit;

FIG. 2 is a perspective view of the electronic device (shown in FIG. 1)in a state in which the battery pack is installed in the main unit;

FIG. 3 is a conceptual diagram of the battery installation part of themain unit;

FIG. 4 is a schematic block diagram showing the configuration of theelectronic device shown in FIG. 1;

FIG. 5 is an enlarged perspective view of a battery pack;

FIG. 6 is a conceptual diagram of a state in which a battery pack isinstalled in a battery installation part;

FIG. 7 is an enlarged perspective view of a battery pack having nodetectable recess;

FIG. 8 is a conceptual diagram of a state in which a battery pack havingno detectable recess is inserted into a battery installation part;

FIG. 9 is a graph showing relationships between the maximum power thatcan be supplied and each of parameters;

FIG. 10 is an enlarged perspective view of another battery pack in adifferent size; and

FIG. 11 is an enlarged perspective view of another battery pack in adifferent size which has no detectable recess.

DESCRIPTION OF THE EMBODIMENTS

Preferred embodiments of the present invention are described below withreference to the accompanying drawings. The following preferredembodiments are applications of an electronic device and battery pack ofthe present invention to a personal computer and a battery pack providedtherein. The coverage of the present invention is not limited to apersonal computer and a battery pack provided therein. The presentinvention is widely applicable to, for example, various types ofelectronic devices such as personal digital assistants (PDA), networkterminals, portable information terminals, workstations, and audiodevices, and battery packs provided therein.

At first, an outline of an electronic device (personal computer) isdescribed below with reference to FIGS. 1 and 2.

An electronic device (personal computer) 100 has a display unit 101 anda main unit 102.

The display unit 101 has a display housing 101 a and a display section101 b fixed to the display housing 101 a.

Hinge projections 103 which project upward are provided at right andleft ends of a rear-end part of the main unit 102. The display unit 101is rotatably supported by the hinge projections 103.

An oblong keyboard 104 is provided on the top surface of the main unit102. The keyboard 104 has a plurality of predetermined operation keys104 a thereon. In the main unit 102, a processor, such as a centralprocessing unit (CPU), which is described later, is provided. Theprocessor performs processing on a signal input by an operation on eachof the operation keys 104 a.

On the top surface of the main unit 102, operating devices differentfrom the operation keys 104 a, for example, so-called “hotkeys” 105 ineach of which a one-touch operation enables execution of software, apointing device 106 on which a movement or the like of a pointer on thedisplay section 101 b can be performed by applying a force in anarbitrary direction with a finger, a left button 107 and a right button108 which correspond to two buttons of a mouse, etc., are arranged.

A power-on button 109 is disposed on the top surface of the main unit102.

A side face 102 a of the main unit 102 has, for example, a recess whichopens on the left and bottom of the main unit 102. This recess is usedas a battery installation part 110. As FIG. 3 shows, the batteryinstallation part 110 has a detecting projection 111 which projects tothe left and which functions as a detector, and a connector 112.

Referring to FIG. 4, the main unit 102 includes a control unit 113 forperforming operation control of the main unit 102, a volatile storageunit functioning as a main storage, a nonvolatile storage unitfunctioning as an auxiliary storage, and an acquiring unit 114. Theseunits are connected by power lines.

The control unit 113 is, for example, a CPU, and has functions ofloading stored information into the volatile storage, performing varioustypes of arithmetic processing, and writing the results of theprocessing in the volatile storage unit.

The volatile storage unit is, for example, a dynamic random accessmemory (DRAM), and is a memory in which stored information vanishes whenpower is removed.

The nonvolatile storage unit is, for example, a hard disk drive, anoptical disk drive, or the like, and is a memory in which storedinformation is stored even when power is removed.

The acquiring unit 114 is, for example, an embedded controller (EC) or asouth bridge (SB) on a mother board. The acquiring unit 114 hasfunctions, such as detection and acquisition of a connection status ofthe battery pack to the main unit 102, and a function of controlling theelectronic device 100 and each unit of a peripheral device of theelectronic device 100 and controlling additional functions, etc.Accordingly, the acquiring unit 114 performs power supply and cutoff forthe control unit 113, the volatile storage unit, the nonvolatile storageunit, the mouse used as an input unit, the keyboard 104, the displaysection 101 b used as an output unit, a printer, etc.

The acquiring unit 114 is connected to the power-on button 109, and hasa function of detecting an operation on the power-on button 109 andinitiating activation of the electronic device 100.

The main unit 102 is provided with an ACPI (Advanced Configuration andPower Interface) 115 as a software layer. The ACPI is a specificationfor consolidating control of power management of the electronic device100. The ACPI 115 is an interface unit forming an ACPI mechanism.

Next, the battery pack for use in the electronic device 100 is describedwith reference to FIGS. 4 and 5.

As shown in FIG. 5, a battery pack 1 has, for example, a substantiallyrectangular flat form. Inside a housing 2, a plurality of cells 4 (shownin FIG. 4), for example, secondary cells such as lithium-ion cells orion-polymer cells, and predetermined portions such as a control circuitsubstrate, are arranged.

A connector 3 is provided on one side face 2 a of the housing 2. Adetectable recess 2 b that functions as a portion to be detected isformed on the side face 2 a of the housing 2.

As shown in FIG. 4, the battery pack 1 includes a storing unit 5. Thestoring unit 5 is, for example, a microcomputer. The storing unit 5retains various types of information concerning cells 4, such asenvironmental conditions such as temperature and humidity, power-supplystates such as battery's remaining capacity and a load status, adeterioration state, and power information. Accordingly, the storingunit 5 constantly detects power information of the cells 4 and alsofunctions as a power information detecting unit.

The cells 4 and storing unit 5 of the battery pack 1 and each unit ofthe main unit 102 are connected to one another by a system bus.

As is described later, when the battery pack 1 is installed in the mainunit 102, the storing unit 5 is connected to the acquiring unit 114 byan input/output (I/O) port 116.

The operation of setting the battery pack 1 in the battery installationpart 110 is described below with reference to FIGS. 6 to 8.

Setting of the battery pack 1 in the battery installation part 110 isperformed by inserting the battery pack 1 into the battery installationpart 110 so that the connector 3 is directed to the battery installationpart 110. When the battery pack 1 is inserted into the batteryinstallation part 110 to its innermost portion, the detecting projection111 of the main unit 102 is relatively inserted into the detectablerecess 2 b of the battery pack 1, as shown in FIG. 6.

When the detecting projection 111 is inserted into the detectable recess2 b, the battery pack 1 is inserted into an innermost end of the batteryinstallation part 110. Then, the connector 3 is connected to a connector112 of the main unit 102, whereby setting of the battery pack 1 in thebattery installation part 110 is completed. After completing the settingof the battery pack 1 in the battery installation part 110, by supplyingpower to the main unit 102, the I/O port 116 displays a mechanicalidentification (ID) of the battery pack 1.

As described above, the detectable recess 2 b is formed on the batterypack 1. Thus, insertion of the detecting projection 111 into thedetectable recess 2 b enables setting of the battery pack 1 in thebattery installation part 110.

However, as shown in FIG. 7, there is also a battery pack “a” which isidentical in size and shape of the battery pack 1 shown in FIG. 1. Inthe battery pack “a”, the power that can be supplied is lower than thatof the battery pack 1. The battery pack “a” does not have the detectablerecess 2 b. Accordingly, as shown in FIG. 8, when the battery pack “a”is inserted in the battery installation part 110, the detectingprojection 111 touches a side face of the battery pack “a”, so thatinsertion of the battery pack “a” into the battery installation part 110is restricted. Since the detecting projection 111 touches the side faceof the battery pack “a”, the battery pack “a” cannot be inserted to aninnermost end of the battery installation part 110, and the connector 3is not connected to the connector 112 of the main unit 102, so that thebattery pack “a” partially projects from the main unit 102.

Therefore, the battery pack “a” cannot be installed in the main unit102. This allows a user to easily know that a wrong type of battery packhas been inserted.

By preventing misinsertion of a battery pack, a problem of data loss inan information processing device, such as a personal computer, can beavoided without causing a situation in which, when the battery pack “a”,in which the power that can be supplied is lower, is installed in thebattery installation part 110, which has large power consumption, thepower unintentionally and suddenly turns off.

In addition, an electronic device having a main unit whose powerconsumption is smaller than that of the main unit 102 is not providedwith a detecting projection. Either the battery pack “a” or the batterypack 1 can be inserted into the main unit of this electronic device.

Moreover, even in the case of designing battery packs, such as thebattery pack 1 and the battery pack “a”, which are identical in size andshape and are different in the power that can be supplied, only byproviding a detecting projection on a main unit of an electronic devicehaving larger power consumption, a battery pack which matches themagnitude of the required power consumption and which corresponds to themain unit can be installed without causing misinsertion. Therefore, inorder to cope with a rise in power consumption of the electronic device,the number of cells in the battery pack does not need to be increased.In addition, enlargement of the battery pack and an increased weight ofthe electronic device, caused by an increased number of cells, can beavoided, and it is not necessary to make major changes in design of thebattery installation part of the main unit.

Next, a communicating operation between the main unit 102 and thestoring unit 5 of the battery pack 1 is described below with referenceto FIG. 4.

When the power-on button 109 is pressed, the acquiring unit 114 detectsthe operation on the power-on button 109, and the operation ofinitiating activation of the electronic device 100 is performed and theacquiring unit 114 supplies power to the control unit 113. The value ofthe I/O port 116, which displays the mechanical ID of the battery pack1, is read by the acquiring unit 114. The acquiring unit 114 acquiresinformation stored in the battery pack 1, for example, power information(the power that can be supplied) configured in design, and transmits theacquired power information to the control unit 113.

After the electronic device 100 is activated, a system bus controller isinitialized, and the address of the battery pack 1 is designated on thesystem bus. This confirms the existence of the battery pack 1. Afterconfirming the existence of the battery pack 1, detection is performedconcerning whether the battery pack 1 and the control unit 113 cancommunicate with each other.

After detecting that the battery pack 1 and the control unit 113 cancommunicate with each other, communication is initiated. The acquiringunit 114 acquires various types of information stored in the batterypack 1, for example, power information, and transmits the acquired powerinformation to the control unit 113.

Based on the transmitted power information, the control unit 113 sets anoptimal operating frequency of the main unit 102. Until the electronicdevice 100 is activated after the power-on button 109 is operated, basedon the power information acquired from the value of the I/O port 116which displays the mechanical ID, the optimal operating frequency of themain unit 102 is set by the control unit 113.

As described above, in the electronic device 100, the power informationof the battery pack 1 is acquired from the storing unit 5 by theacquiring unit 114, and the operation of the main unit 102 is controlledby the control unit 113 based on the power information of the batterypack 1 acquired by the acquiring unit 114. Thus, for example, a problemof data loss in an information processing device, such as a personalcomputer, can be avoided without causing a situation in which the powerunintentionally and suddenly turns off.

In addition, it is not necessary to provide a control circuit, such as apower saving circuit, in the main unit 102 in order to prevent the powerfrom suddenly turns off. This can reduce the production cost requiredfor the electronic device 100.

Cases in which the power information configured in design of the batterypack 1 and in which power information obtained when the electronicdevice 100 is activated have been described. However, the maximum powerthat can be supplied of the battery pack 1 to the main unit 102sequentially changes in accordance with surrounding environments or alapse of duration of use.

FIG. 9 is a graph showing relationships among the maximum power that canbe supplied of the battery pack 1 and parameters.

As shown in FIG. 9, the maximum power that can be supplied of thebattery pack 1 increases as an ambient temperature around the batterypack 1 increases. It increases as the voltage (cell voltage) of thebattery pack 1 increases. It increases as a deterioration factor of thebattery pack 1 decreases.

Accordingly, in the electronic device 100, by using the storing unit 5of the battery pack 1, the maximum power that can be supplied iscalculated based on constant detection of the ambient temperature,voltage, and deterioration factor, the calculated value is written in astorage area (RAM) of the storing unit 5, and the written powerinformation is acquired and transmitted to the control unit 113 by theacquiring unit 114.

The acquisition and transmission of the power information by theacquiring unit 114 are continuously or intermittently performed when theelectronic device 100 is activated. When the acquisition andtransmission are intermittently performed, they are performed atintervals of, for example, eight seconds. Based on the continuously orintermittently transmitted power information, the control unit 113changes the set optimal operating frequency each time and performsoperation control of the main unit 102.

Therefore, in the electronic device 100, operation control can beoptimized in response to a state of use on each occasion.

A case in which the main unit 102 is provided with the detectingprojection 111 as a detecting part and the battery pack 1 is providedwith the detectable recess 2 b as a detectable part has been described.Conversely, the display unit 101 can be provided with a detecting recessas a detecting part and the battery pack 1 can be provided with adetectable projection as a detectable part.

The detecting part and the detectable part can be formed by, forexample, optical or magnetic devices such as optical sensors or magneticsensors without using mechanical parts such the detecting projection 111as the detecting part and the detectable recess 2 b as the detectablepart.

The sizes and shapes of the battery pack 1 and the battery pack “a” arenot limited to those shown in FIGS. 5 and 7. For example, the batterypack 1A shown in FIG. 10 and the battery pack “b” shown in FIG. 11,which are smaller in size than the battery pack 1 and the battery pack“a”, are usable. In the battery pack 1A, the power that can be suppliedis larger than that of the battery pack “b”. The battery pack 1A isprovided with a detectable recess 2C or a detectable projection, and thebattery pack “b” is not provided with a detectable recess and adetecting projection.

The specific shapes and structures of the parts shown in the aboveembodiments are simple examples of embodying the present invention inpracticing the present invention. Based on these, the technical scope ofthe present invention should not be interpreted in a limited manner.

1. (canceled)
 2. An electronic device driven by power supplied from abattery pack installed in a main unit of said electronic device,comprising: a storing unit, provided in the battery pack, for storingpower information of the battery pack; an acquiring unit, provided inthe main unit, for acquiring the power information of the battery pack;and a control unit, provided in the main unit, for controlling afrequency of the main unit based on the power information of the batterypack acquired by said acquiring unit.
 3. The electronic device accordingto claim 2, wherein the power information of the battery pack isregularly stored by said storing unit, and the regularly stored powerinformation is continuously or intermittently acquired by said acquiringunit.
 4. The electronic device according to claim 2, wherein the powerinformation including a maximum amount of power that can be delivered bythe battery pack.
 5. The electronic device according to claim 4, whereinthe maximum amount of power is a maximum amount of energy per unit timethat can be delivered by the battery pack.
 6. The electronic deviceaccording to claim 4, wherein the maximum amount of power is calculatedbased on at least one of an ambient temperature, voltage, anddeterioration factor.
 7. The electronic device according to claim 2,wherein the battery pack has thereon a detectable part for enablingdetection of the type of the battery pack, the main unit has thereon adetecting part for reading the detectable part to detect the type of thebattery pack, and the control unit controls the operation of the mainunit based on power information stored in the battery pack, whose typeis detected.
 8. The electronic device according to claim 7, furthercomprising: a housing for the battery pack with, on an outer surfacethereof, one of a detectable projection and a detectable recess as thedetectable part, wherein the main unit has, thereon, as the detectingpart, one of a detecting recess into which the detectable projection isto be inserted and a detecting projection to be inserted into thedetectable recess.
 9. A method comprising: storing power information ofa battery pack installed in a main unit of an electronic device in thebattery pack; acquiring the power information of the battery pack by themain unit; and controlling a frequency of the main unit based on thepower information of the battery pack acquired by said acquiring.